1. Field of the Invention
The present invention relates to a fuel injection apparatus (hereinafter, referred to as an injector) for injecting fuel in an internal combustion engine (hereinafter, referred to as an engine).
2. Description of Related Art
Promotion of atomization of fuel, which is injected directly into a combustion chamber of an engine or is injected into an intake pipe connected to the combustion chamber of the engine, is important to reduce noxious components contained in exhaust gases and to increase performance of the engine or to improve fuel consumption.
For example, in an injector disclosed in Japanese Unexamined Patent Publication No. 11-70347, which corresponds to U.S. Pat. No. 5,931,391, injection holes are provided in an injection hole plate. The injection hole plate is provided separately from a valve body, which receives a valve member. In this case, shapes and positions of the injection holes can be more easily changed at the time of designing the injector, so that a spray pattern of fuel discharged from the corresponding injection hole can be more freely selected.
In the injector disclosed in Japanese Unexamined Patent Publication No. 11-70347, fuel supplied from a fuel passage, which is defined in the valve body, is directly supplied to the injection hole plate, and turbulence is created in the fuel flow supplied from the fuel passage before entering the injection holes of the injection hole plate. In this way, atomization of injected fuel is promoted. However, in this case, fuel, which passes the corresponding injection hole, is influenced by an inner peripheral wall of the injection hole, which tends to rectify the fuel flow. Thus, a degree of turbulence of the fuel flow is reduced, and thus atomization of injected fuel is limited.